Field of the Invention
The present invention relates to an image processing apparatus and method and an image capturing apparatus and, more particularly, to an image processing apparatus and method and an image capturing apparatus that perform digital dodging.
Description of the Related Art
A so-called, wide-dynamic-range camera is drawing attention. This camera has a wide dynamic range and can clearly capture both an extremely bright object and dark object coexisting in the same angle of view. Various tone correction methods have been examined as a method capable of this wide-dynamic-range image capturing. For example, a dodging process performed in a darkroom is available for silver halide photographs, and there is a technique (digital dodging process) that implements this dodging process as digital image processing, and corrects an object having a difference between brightness and darkness, particularly, an object in backlight. Also, the digital dodging process is performed by changing the gain in order to adjust the strength.
In Japanese Patent No. 4376352, a histogram is divided, and the tone of a low-luminance portion is corrected such that the slope of the tone characteristic of a portion where luminances are distributed most is steep. There is also disclosed a technique that adjusts the interval of division levels in ascending order of luminance level.
Unfortunately, if the slope of the level is simply steepened as in the related art disclosed in Japanese Patent No. 4376352, the tone may largely become discrete and deteriorate the image quality.